Önal, Mehmetvan den Heuvel, W.Dereli, Meryem MerveAlbey, Erinç2023-08-172023-08-172023-07-010377-2217http://hdl.handle.net/10679/8712https://doi.org/10.1016/j.ejor.2022.11.016We introduce a multiple-item economic lot sizing problem where items are produced through the fermentation of some raw materials. Fermentation takes place in specialized tanks that have finite capacities, and duration of the fermentation process is item dependent. When fermentation starts, the tanks are not available for the duration of the fermentation process. We analyze the complexity of this problem under various assumptions on the number of items and tanks. In particular, we show that several cases of the problem are (strongly) NP-hard, and we propose polynomial time algorithms to some single item cases. In addition, we propose a quick and simple heuristic approach for one of the multiple item cases.engrestrictedAccessarticle308116618200099204940000110.1016/j.ejor.2022.11.016Complexity analysisEconomic lot sizingFermentation tank schedulingProduction2-s2.0-85143509528